Geology and hydrocarbon potential of offshore SE Somalia

Interpretation of a 20550 line km 2D seismic survey acquired in 2014 by Soma Oil and Gas in the deep water offshore area of SE Somalia has identified three previously undocumented sedimentary provinces – Jubba Deep, Mogadishu Deep and Mid Somalia High – all of which have distinctive geological characteristics. Well and stratigraphic controls are limited, with inferred lithologies largely based on seismic stratigraphic interpretation. The Jubba Deep has a thick Late Cretaceous–Early Tertiary deltaic section deformed by major gravitational collapses in the Paleocene-age Kismaayo Thrust Belt (KTB) and the Pliocene-age Baraawe Thrust Belt (BTB). It is proposed that the KTB has significant hydrocarbon potential in deltaic and pro-delta sands trapped in thrust anticlines and sourced with oil from Mid-Cretaceous mobile shales. The Mogadishu Deep Basin has a thick Mesozoic and Tertiary section but is missing the thick deltaics seen in the Jubba Basin. Volcanics are present in this basin. The Mid Somalia High has a relatively thinner sedimentary section where Cretaceous and Jurassic reservoirs and potential source rocks are at moderate burial depths. An extensive post-rift Mid–Late Jurassic carbonate platform is developed here with potential hydrocarbon targets in interpreted reefs and shoal facies.